<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html>
<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>FlipBar.qml 示例文件 | Qt 5.12 5.12.3</title>
  <link rel="stylesheet" type="text/css" href="style/offline-simple.css" />
  <script type="text/javascript">
    document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css");
    // loading style sheet breaks anchors that were jumped to before
    // so force jumping to anchor again
    setTimeout(function() {
        var anchor = location.hash;
        // need to jump to different anchor first (e.g. none)
        location.hash = "#";
        setTimeout(function() {
            location.hash = anchor;
        }, 0);
    }, 0);
  </script>
</head>
<body>
<div class="header" id="qtdocheader">
  <div class="main">
    <div class="main-rounded">
      <div class="navigationbar">
        <table><tr>
<td ><a href="index.html">Qt 5.12</a></td><td ><a href="qtdoc-demos-tweetsearch-example.html">Qt Quick Demo - Tweet Search</a></td><td >FlipBar.qml 示例文件</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.12.3 参考指南</td>
        </tr></table>
      </div>
    </div>
<div class="content">
<div class="line">
<div class="content mainContent">
<div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div>
<h1 class="title">FlipBar.qml 示例文件</h1>
<span class="subtitle">demos/tweetsearch/content/FlipBar.qml</span>
<!-- $$$demos/tweetsearch/content/FlipBar.qml-description -->
<div class="descr"> <a name="details"></a>
<pre class="qml">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2017 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** &quot;AS IS&quot; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.&quot;
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/</span>

  import QtQuick 2.0

  <span class="type"><a href="../qtquick/qml-qtquick-item.html">Item</a></span> {
      <span class="name">id</span>: <span class="name">container</span>
      property <span class="type"><a href="../qtqml/qml-int.html">int</a></span> <span class="name">animDuration</span>: <span class="number">300</span>
      property <span class="type"><a href="../qtquick/qml-qtquick-item.html">Item</a></span> <span class="name">front</span>: <span class="name">Item</span> {}
      property <span class="type"><a href="../qtquick/qml-qtquick-item.html">Item</a></span> <span class="name">back</span>: <span class="name">Item</span> {}
      property <span class="type"><a href="../qtqml/qml-real.html">real</a></span> <span class="name">factor</span>: <span class="number">0.1</span> <span class="comment">// amount the edges fold in for the 3D effect</span>
      property <span class="type">alias</span> <span class="name">delta</span>: <span class="name">effect</span>.<span class="name">delta</span>
      property <span class="type"><a href="../qtquick/qml-qtquick-item.html">Item</a></span> <span class="name">cur</span>: <span class="name">frontShown</span> ? <span class="name">front</span> : <span class="name">back</span>
      property <span class="type"><a href="../qtquick/qml-qtquick-item.html">Item</a></span> <span class="name">noncur</span>: <span class="name">frontShown</span> ? <span class="name">back</span> : <span class="name">front</span>

      <span class="keyword">function</span> <span class="name">swap</span>() {
          var tmp = <span class="name">front</span>;
          <span class="name">front</span> <span class="operator">=</span> <span class="name">back</span>;
          <span class="name">back</span> <span class="operator">=</span> <span class="name">tmp</span>;
          <span class="name">resync</span>();
      }

      <span class="name">width</span>: <span class="name">cur</span>.<span class="name">width</span>
      <span class="name">height</span>: <span class="name">cur</span>.<span class="name">height</span>
      <span class="name">onFrontChanged</span>: <span class="name">resync</span>();
      <span class="name">onBackChanged</span>: <span class="name">resync</span>();

      <span class="keyword">function</span> <span class="name">resync</span>() {<span class="comment">//TODO: Are the items ever actually visible?</span>
          <span class="name">back</span>.<span class="name">parent</span> <span class="operator">=</span> <span class="name">container</span>;
          <span class="name">front</span>.<span class="name">parent</span> <span class="operator">=</span> <span class="name">container</span>;
          <span class="name">frontShown</span> ? <span class="name">back</span>.<span class="name">visible</span> <span class="operator">=</span> <span class="number">false</span> : <span class="name">front</span>.<span class="name">visible</span> <span class="operator">=</span> <span class="number">false</span>;
      }

      property <span class="type"><a href="../qtqml/qml-bool.html">bool</a></span> <span class="name">frontShown</span>: <span class="number">true</span>

      <span class="name">onFrontShownChanged</span>: {
          <span class="name">back</span>.<span class="name">visible</span> <span class="operator">=</span> !<span class="name">frontShown</span>
          <span class="name">front</span>.<span class="name">visible</span> <span class="operator">=</span> <span class="name">frontShown</span>
      }

      <span class="keyword">function</span> <span class="name">flipUp</span>(start) {
          <span class="name">effect</span>.<span class="name">visible</span> <span class="operator">=</span> <span class="number">true</span>;
          <span class="name">effect</span>.<span class="name">sourceA</span> <span class="operator">=</span> <span class="name">effect</span>.<span class="name">source1</span>
          <span class="name">effect</span>.<span class="name">sourceB</span> <span class="operator">=</span> <span class="name">effect</span>.<span class="name">source2</span>
          <span class="keyword">if</span> (<span class="name">start</span> <span class="operator">==</span> <span class="name">undefined</span>)
              <span class="name">start</span> <span class="operator">=</span> <span class="number">1.0</span>;
          <span class="name">deltaAnim</span>.<span class="name">from</span> <span class="operator">=</span> <span class="name">start</span>;
          <span class="name">deltaAnim</span>.<span class="name">to</span> <span class="operator">=</span> <span class="number">0.0</span>
          <span class="name">dAnim</span>.<span class="name">start</span>();
          <span class="name">frontShown</span> <span class="operator">=</span> <span class="number">false</span>;
      }

      <span class="keyword">function</span> <span class="name">flipDown</span>(start) {
          <span class="name">effect</span>.<span class="name">visible</span> <span class="operator">=</span> <span class="number">true</span>;
          <span class="name">effect</span>.<span class="name">sourceA</span> <span class="operator">=</span> <span class="name">effect</span>.<span class="name">source1</span>
          <span class="name">effect</span>.<span class="name">sourceB</span> <span class="operator">=</span> <span class="name">effect</span>.<span class="name">source2</span>
          <span class="keyword">if</span> (<span class="name">start</span> <span class="operator">==</span> <span class="name">undefined</span>)
              <span class="name">start</span> <span class="operator">=</span> <span class="number">0.0</span>;
          <span class="name">deltaAnim</span>.<span class="name">from</span> <span class="operator">=</span> <span class="name">start</span>;
          <span class="name">deltaAnim</span>.<span class="name">to</span> <span class="operator">=</span> <span class="number">1.0</span>
          <span class="name">dAnim</span>.<span class="name">start</span>();
          <span class="name">frontShown</span> <span class="operator">=</span> <span class="number">true</span>;
      }

      <span class="type"><a href="../qtquick/qml-qtquick-shadereffect.html">ShaderEffect</a></span> {
          <span class="name">id</span>: <span class="name">effect</span>
          <span class="name">width</span>: <span class="name">cur</span>.<span class="name">width</span>
          <span class="name">height</span>: <span class="name">cur</span>.<span class="name">height</span>
          property <span class="type"><a href="../qtqml/qml-real.html">real</a></span> <span class="name">factor</span>: <span class="name">container</span>.<span class="name">factor</span> <span class="operator">*</span> <span class="name">width</span>
          property <span class="type"><a href="../qtqml/qml-real.html">real</a></span> <span class="name">delta</span>: <span class="number">1.0</span>

          <span class="name">mesh</span>: <span class="name">GridMesh</span> { <span class="name">resolution</span>: <span class="name">Qt</span>.<span class="name">size</span>(<span class="number">8</span>,<span class="number">2</span>) }

          SequentialAnimation on <span class="name">delta</span> {
              <span class="name">id</span>: <span class="name">dAnim</span>
              <span class="name">running</span>: <span class="number">false</span>
              <span class="type"><a href="../qtquick/qml-qtquick-numberanimation.html">NumberAnimation</a></span> {
              <span class="name">id</span>: <span class="name">deltaAnim</span>
              <span class="name">duration</span>: <span class="name">animDuration</span><span class="comment">//expose anim</span>
              }
          }

          property <span class="type"><a href="../qtqml/qml-variant.html">variant</a></span> <span class="name">sourceA</span>: <span class="name">source1</span>
          property <span class="type"><a href="../qtqml/qml-variant.html">variant</a></span> <span class="name">sourceB</span>: <span class="name">source1</span>
          property <span class="type"><a href="../qtqml/qml-variant.html">variant</a></span> <span class="name">source1</span>: <span class="name">ShaderEffectSource</span> {
              <span class="name">sourceItem</span>: <span class="name">front</span>
              <span class="name">hideSource</span>: <span class="name">effect</span>.<span class="name">visible</span>
          }

          property <span class="type"><a href="../qtqml/qml-variant.html">variant</a></span> <span class="name">source2</span>: <span class="name">ShaderEffectSource</span> {
              <span class="name">sourceItem</span>: <span class="name">back</span>
              <span class="name">hideSource</span>: <span class="name">effect</span>.<span class="name">visible</span>
          }

          <span class="name">fragmentShader</span>: <span class="string">&quot;
              uniform lowp float qt_Opacity;
              uniform sampler2D sourceA;
              uniform sampler2D sourceB;
              uniform highp float delta;
              varying highp vec2 qt_TexCoord0;
              void main() {
                  highp vec4 tex = vec4(qt_TexCoord0.x, qt_TexCoord0.y * 2.0, qt_TexCoord0.x, (qt_TexCoord0.y-0.5) * 2.0);
                  highp float shade = clamp(delta*2.0, 0.5, 1.0);
                  highp vec4 col;
                  if (qt_TexCoord0.y &lt; 0.5) {
                      col = texture2D(sourceA, tex.xy) * (shade);
                  } else {
                      col = texture2D(sourceB, tex.zw) * (1.5 - shade);
                      col.w = 1.0;
                  }
                  gl_FragColor = col * qt_Opacity;
              }
          &quot;</span>
          property <span class="type"><a href="../qtqml/qml-real.html">real</a></span> <span class="name">h</span>: <span class="name">height</span>
          <span class="name">vertexShader</span>: <span class="string">&quot;
          uniform highp float delta;
          uniform highp float factor;
          uniform highp float h;
          uniform highp mat4 qt_Matrix;
          attribute highp vec4 qt_Vertex;
          attribute highp vec2 qt_MultiTexCoord0;
          varying highp vec2 qt_TexCoord0;
          void main() {
              highp vec4 pos = qt_Vertex;
              if (qt_MultiTexCoord0.y == 0.0)
                  pos.x += factor * (1. - delta) * (qt_MultiTexCoord0.x * -2.0 + 1.0);
              else if (qt_MultiTexCoord0.y == 1.0)
                  pos.x += factor * (delta) * (qt_MultiTexCoord0.x * -2.0 + 1.0);
              else
                  pos.y = delta * h;
              gl_Position = qt_Matrix * pos;
              qt_TexCoord0 = qt_MultiTexCoord0;
          }&quot;</span>

      }
  }

</pre>
</div>
<!-- @@@demos/tweetsearch/content/FlipBar.qml -->
        </div>
       </div>
   </div>
   </div>
</div>
<div class="footer">
   <p>
   <acronym title="Copyright">&copy;</acronym> 2019 The Qt Company Ltd.
   Documentation contributions included herein are the copyrights of
   their respective owners.<br/>    The documentation provided herein is licensed under the terms of the    <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation    License version 1.3</a> as published by the Free Software Foundation.<br/>    Qt and respective logos are trademarks of The Qt Company Ltd.     in Finland and/or other countries worldwide. All other trademarks are property
   of their respective owners. </p>
</div>
</body>
</html>
